请教新概念英语第三册but they lead mysterious lives of their own as wel

请教新概念英语第三册but they lead mysterious lives of their own as wel but they lead mysterious lives of their own as well. 中的lead是 but they lead mysterious lives of their own as well.这里的为什么用o 为什么说They lead mysterious lives of their own而不是lead their own They lead mysterious lives of their own.他们有着自己神秘的生活方式,Lives 翻译They have their lives to lead. They treated me as their own child. 6As they haven't a child of their own,they're going to ____ 10、As they can't have a child of their own,they're going to They believe that their famil members don't know them as wel They belive that their family members don’t know them as wel 请教三个月学完新概念英语第三册可能吗?